EHD Enhanced Heat Transfer in a Vertical Annulus

The preliminary experimental results of the effect of an electrostatic field on turbulent aided mixed convection in a short vertical annulus are reported herein. A dielectric liquid (FC-72 by 3M) is used as working fluid. The local heat transfer improvement is obtained by inserting appropriate points on the inner surface of the annulus, generally acting as the positive electrode, while the surrounding pipe is grounded. A high voltage (up to 22 kV) is established between the two surfaces. The heat exchange revealed to be highly enhanced by this technique, thus providing encouraging indications for practical applications.